package org.raymond.iworks.study.basic.designpattern.facade;

/**
 * @author raymond
 * @version V1.0
 * @Description: TODO
 */
public class Screen {
    private Screen(){}
    private final static class Holder {
        private final static Screen instance = new Screen();
    }
    public static Screen getInstance(){
        return Screen.Holder.instance;
    }
    public void up(){
        System.out.println("screen up");
    }
    public void down(){
        System.out.println("screen down");
    }
}
